oxacillin

REMS

Treatment of the following infections due to penicillinase-producing staphylococci:
- Respiratory tract infections,
- Sinusitis,
- Skin and skin structure infections,
- Bone and joint infections,
- Urinary tract infections,
- Endocarditis,
- Bacteremia,
- Meningitis.

Action ⬆ ⬇

Bind to bacterial cell wall, leading to cell death. Not inactivated by penicillinase enzymes.

Therapeutic effects:

Bactericidal action.

Spectrum:

Active against most gram-positive aerobic cocci.
Spectrum is notable for activity against:
- Penicillinase-producing strains of Staphylococcus aureus,
- Staphylococcus epidermidis.
Not active against methicillin-resistant bacteria.

Pharmacokinetics ⬆ ⬇

Absorption: Completely absorbed following IV administration; well absorbed from IM sites.

Distribution: Widely distributed; penetration into CSF is minimal but sufficient in the presence of inflamed meninges; cross the placenta and enter breast milk.

Protein Binding: 94% to albumin

Metabolism/Excretion: Partially metabolized by the liver (9%), partially excreted unchanged by the kidneys.

Half-Life: Neonates: 1.6 hr; Children up to 2 yr: 0.9–1.8 hr; Adults: 0.3–0.8 hr (↑ in severe hepatic impairment).

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
Oxacillin IM	rapid	30 min	4–6 hr
Oxacillin IV	rapid	end of infusion	4–6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Previous hypersensitivity to penicillins (cross-sensitivity exists with cephalosporins and other beta-lactam antibiotics).

Use Cautiously in:

Severe renal or hepatic impairment.
Pedi: Hematuria and azotemia have occurred in neonates and infants receiving high-dose oxacillin

Adv. Reactions/Side Effects ⬆ ⬇

Derm: rash, urticaria

GI: diarrhea, epigastric distress, nausea, vomiting, Clostridioides difficile-associated diarrhea (CDAD)

GU: interstitial nephritis

Hemat: eosinophilia, leukopenia

Local: pain at IM site, phlebitis at IV site

Neuro: SEIZURES

Misc: ANAPHYLAXIS AND SERUM SICKNESSALLERGIC REACTIONS INCLUDING , superinfection

Interactions ⬆ ⬇

Drug-drug:

Oxacillin may ↓ effectiveness of oral contraceptive agents.
Probenecid↓ renal excretion and ↑ blood levels of oxacillin (therapy may be combined for this purpose).
Concurrent use with methotrexate↓ methotrexate elimination and ↑ risk of serious toxicity.
Tetracyclinesmay ↓ effectiveness of oxacillin

Route/Dosage ⬆ ⬇

IM IV (Adults and Children ≥40 kg): 250–2000 mg q 4–6 hr (up to 12 g/day).
IM IV (Children <40 kg): 100–200 mg/kg/day divided q 4–6 hr, maximum: 12 g/day.
IM IV (Neonates <1200 g): —50 mg/kg/day divided q 12 hr.
IM IV (Neonates ≥2 kg): —75 mg/kg/day divided q 8 hr for the first 7 days of life, then 100 mg/kg/day divided q 6 hr.
IM IV (Neonates 1.2–2 kg): —50 mg/kg/day divided q 12 hr for the first 7 days of life, then 75 mg/kg/day divided q 8 hr.

Availability ⬆ ⬇

(Generic available)

Powder for injection: 1 g/vial; 2 g/vial; 10 g/vial

Assessment ⬆ ⬇

Assess for infection (vital signs; appearance of wound, sputum, urine, and stool; WBC) at beginning of and throughout therapy.
Obtain a history before initiating therapy to determine previous use of and reactions to cephalosporins or other beta-lactam antibiotics. Persons with a negative history of penicillin sensitivity may still have an allergic response.
Obtain specimens for culture and sensitivity prior to initiating therapy. First dose may be given before receiving results.
Observe patient for signs and symptoms of anaphylaxis (rash, pruritus, laryngeal edema, wheezing, abdominal pain). Discontinue the drug and notify the physician or other health care professional immediately if these occur. Keep epinephrine, an antihistamine, and resuscitation equipment close by in the event of an anaphylactic reaction.
Assess vein for signs of irritation and phlebitis. Change IV site every 48 hr to prevent phlebitis.

Lab Test Considerations:

May cause leukopenia and neutropenia, especially with prolonged therapy or hepatic impairment.
- May cause positive direct Coombs’ test result.
- May cause ↑ AST, ALT, LDH, and serum alkaline phosphatase concentrations.

Implementation ⬆ ⬇

IM: To reconstitute for IM or IV use, add 1.4 mL of sterile water for injection to each 250-mg vial, 2.7 mL to each 500-mg vial, 5.7 mL to each 1-g vial, 11.5 mL to each 2-g vial, and 23 mL to each 4-g vial, for a concentration of 250 mg/1.5 mL. Stable for 3 days at room temperature or 7 days if refrigerated.

IV Administration:

Diluent: Further dilute each reconstituted 250-mg or 500-mg vial with 5 mL of sterile water or 0.9% NaCl for injection, 10 mL for each 1-g vial, 20 mL for each 2-g vial, and 40 mL for each 4-g vial.
Rate: Administer slowly over 10 min.
Intermittent Infusion: Diluent: Dilutewith 0.9% NaCl, D5W, D5/0.9% NaCl, or LR.Concentration: 0.5–40 mg/mL.
Rate: May be infused for up to 6 hr.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication around the clock and to finish the drug completely as directed, even if feeling better. Missed doses should be taken as soon as remembered. Advise patient that sharing of this medication may be dangerous.
Advise patient to report signs of superinfection (black, furry overgrowth on the tongue; vaginal itching or discharge; loose or foul-smelling stools) and allergy.
Instruct patient to notify health care professional if fever and diarrhea develop, especially if stool contains blood, pus, or mucus. Advise patient not to treat diarrhea without consulting health care professional.
Instruct patient to notify health care professional if symptoms do not improve.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇